Reading Milestones is a research-based program, and it does provide materials that are useful for teaching a variety of literacy components. Taken together, all six levels serve as as leveled library that provides texts on all types of topics. I use the program mostly to teach comprehension, but it can be used to teach vocabulary, spelling, and other skills. This program is good for secondary readers who are on a 1.5 to 3.0 grade level (it maxes out at 3.5), but the primer and early first grade texts provided are too low-interest, in my opinion, for secondary students. For younger students, however, the lower levels of the program would work well. The handbooks provide precise instructions and exercises for making the most out of each story - it takes some work, but it does a good job of teaching comprehension.